1. Field of the Invention
This invention relates to an audio unit for use in a game machine and to an information recording medium that can be used in such a device.
2. Description of the Related Art
In game machines, sound effects and other audio constitute an extremely important part of the configuration. The role of audio is first to give the game player a sense of realism. Such audio produces a synergistic effect with the video images, etc., according to each scene. Audio is also used extensively to inform the player that the game has started or ended, or that game points have been scored.
Another important role of sound effects and other audio, when they can be heard by people other than the actual game players, is to promote interest in the game. This is especially important for commercially operated game machines. In such game machines, when the machine is running idly with no one playing it, a demonstration is carried on which displays highlights of the game. The sounds generated at this time can create interest in the game in potential players. Audio thus occupies a position of extreme importance.
Conventionally, such audio, for which stereo sound is primarily used, is controlled so as to change the volume balance between speakers deployed on the left and right sides relative to the players, corresponding respectively to sounds that should be generated to the left and right in the virtual game space. Control is also effected in the near-far dimension by altering the sound volume itself. Sound becomes smaller the greater the distance from the sound origin to the listener becomes. Sound volume control is thus implemented in game machines also in accordance with this natural principle. By means of such control, a sense of distance can be produced by the sound effects.
There is a problem with controlling the sound volume according to near-far distances in virtual game space, however. When sound effects are generated with images involving a distant explosion, the sound volume becomes small and impact is lacking. When the game machine is in demonstration mode, in particular, the generation of sound effects having no force of impact will not be very effective in promoting interest in playing the game.
An object of the present invention is to provide a game machine audio device wherewith sound can be obtained which imparts a sense of distance in virtual game space without changing the sound volume much at all, thus resolving the problems with the prior art described in the foregoing.
In order to achieve the object noted above, the present invention is a game machine audio device wherein the frequency components of generated sounds are altered according to the distance between the sound generation position and listening position in virtual game space.
It is efficacious to alter the frequency components in audio coming over different distances in virtual game space. As sounds are generated from greater and greater distances in virtual game space, it is effective to attenuate the high portions of the frequency components thereof while amplifying the low portions of the frequency components thereof.
It is desirable that changes in frequency components of sound be processed using a digital signal processor.
In order to achieve the object stated earlier, moreover, an information recording medium wherein information relating to the game is stored can be used in the device described in the foregoing in such manner as to contain information for finding distances from sound generation positions to listening positions in virtual game space and information for altering the frequency components of generated sounds based on the distances so found.